U.S. Pat. No. 3,755,899 describes a control unit for supporting and selectively distributing high pressure air to a plurality of high-pressure air-driven dental handpieces. An important objective of the present invention is to provide a similar type of control unit for supporting the electrically energized type of handpieces, and which selectively supplies high-pressure air from a common controller to pressure-sensitive impedance elements which control the handpieces. This permits the electrical handpieces to be interfaced in the control unit and used, either in conjunction with, or as a replacement for, the air-driven type of handpieces, all of which are controlled by the common air pressure controller.
The term "dental handpiece" as used herein is not intended to be limited to the rotating devices such as drills and burnishers, but is also intended to embrace a wide variety of dental devices such as vibrators, ultrasonic scaling devices, scalpels, electrosurgery devices, fiber optics and other lighting devices, and the like.
The control of the present invention permits such electrical dental handpieces to be interfaced in a common control with the air pressure type, and all may be controlled by a common air pressure controller. In the case of the electrically energized devices, the air pressure from the controller is used to control a pressure-sensitive impedance which, in turn, controls the electrical energy supplied to the selected handpiece.